One of the interesting aspects of this RED Gardens project is that it offers the opportunity
to examine vegetables grown in gardens that are following different methods.
I'd love to say that I'm on top of all these methods, that everything's going really well
and adopting them to this context, but I'm not really there yet.
This is partially due to the crazy weather that we've had this season, and I have also
been too busy to attend to some of the details and I've made a few mistakes along the way.
But I still think it's useful to examine the growth of particular crops as it helps to
identify issues within the various methods, to figure out what’s going well and what's
going poorly.
Within this context it was quite interesting to examine the growth and eventual yields
of a batch of cauliflower that I planted in four of the family scale gardens:
the Extensive, Intensive, No-Dig and Polytunnel Gardens.
One did quite well, two were reasonably decent and one was embarrassingly poor,
but I think that's mostly my fault as I was trying something new.
Cauliflower can be a tricky crop to grow well, and I haven’t had consistent success with
it in the past.
All of the plants for these gardens were from one batch that I sowed into soil blocks on
the 21st of March.
It ended up being a cold and delayed spring, and because I was so busy, I didn’t get
a chance to transplant these plants into the gardens until the first week of May, which
was later than I would have wanted.
So, the plants didn’t get a great start, but they were still in decent shape; they
weren’t root bound, but they were definitely reaching the limits of the soil blocks.
Before transplanting, the beds in each of these gardens was prepared in a different
method, with different amounts and types of fertility being added.
For the Extensive Garden, I dug compost and chicken manure pellets into the stations marked
out for each of the plants.
I double-dug the entire bed in the Intensive Garden, and topped it off with a decent layer
of compost.
I would have preferred using twice as much compost, but I didn’t have enough, so I
added some chicken manure pellets to supplement the fertility.
For the No-Dig Garden, I spread a 40mm thick layer of compost over the entire bed, on top
of a layer of apple pulp, which I’d used as an overwintering mulch, and this ended
up not being a great idea.
The bed in the Polytunnel Garden was well cultivated earlier in the spring, incorporating
a fair amount of compost, Soft Rock Phosphate, some seaweed meal, and some chicken manure pellets.
I then sowed an early batch of rocket or arugula in this bed, and ended up transplanting the
cauliflower plants into spaces cleared in this carpet of salad greens.
The plant spacing was also different in each of the gardens, which is important as the
distance between the plants can affect the size of the head that’s eventually harvested.
In general, the closer the plants are together, the smaller the individual heads will be,
but with potentially the same yield over a given area.
Each of the plants in the Extensive Garden had lots of room to grow really big.
This was partially because the cauliflower plants had several weeks head start to become
really established, before they had to compete with other plants transplanted into the adjacent rows.
The plants in the Intensive Garden were much closer together, with a density of about twice
as many plants per square meter as with the Extensive Garden.
I used a moderate plant spacing for the No-Dig Garden, somewhere between the Extensive and
Intensive Gardens, and there was only slight competition form adjacent crops.
The Polytunnel Garden had the highest plant density out of all of the gardens, and there
was also a fair amount of competition from the rocket plants for the first week or so,
as well as from an adjacent crop of tomatoes later in the season.
After transplanting, I covered all of the plants outside with a crop cover, to protect
from caterpillars and flee beetles, but I didn’t cover the crops in the polytunnel.
For the first few weeks that the plants were in the ground, we had reasonably good weather
conditions, but then it turned unseasonably hot and dry for the remainder of the period
that they were growing, right up until after the last cauliflower was harvested near the
end of July.
We even had a short heatwave at the end of June, which could cause problems for this
crop which normally prefers cooler growing conditions.
But then a heatwave in Ireland isn’t that hot, although it did get exceptionally hot
in the polytunnel.
The lack of rain was probably a more critical issue, although I didn’t notice any wilting
or other obvious signs of water stress.
There were signs of nutritional deficiencies though, including the purple tinting of the
older leaves that is characteristic of phosphorous deficiencies, and I suspect this was because
I didn’t provide enough water at some point during the extended dry period.
This seems to be a critical issue with the calcareous soil that I’m working with.
The high pH of 7.5 can restrict the availability of phosphorus and some of the other nutrients,
a situation that seems to be made worse when the soil moisture is too low.
There was phosphorus in the soil, its just that the plants couldn’t get access to it
fast enough.
Given these conditions, I was reasonably pleased with what I was able to harvest from the Intensive Garden.
Out of the 8 plants, 5 of them produced reasonably sized, good shaped heads, one was a little
small, one I harvested a little late and it had grown past its prime, and another one
developed a strange surface mould, which made it inedible.
There was also an interesting pink coloration around the edge of some of the heads, and
pink dots in the middle of some of the curds or immature flower buds.
Apparently this is caused by exposure to the sun if the heads aren’t shaded out by the
leaves being folded over or tied up, but apparently it can also be caused by significant fluctuations
in temperatures.
Either way, the heads are still edible.
In addition to the signs of phosphorous deficiencies in the older leaves, a lot of the younger
leaves had burnt or decayed tips.
I’m not sure if this was due to a lack of soil moisture or some other deficiencies,
but I imagine that the situation was exacerbated by the plants being spaced so close together.
All of these issues were signs that conditions could definitely have been better, and if
they were, I’d expect a better crop.
The cauliflower crop in the polytunnel did better than I thought it would, given the
heat and the not great start for the crop.
Transplanting the cauliflower in amongst the existing rocket plants was probably not a
great idea, as it seems to have stressed the plants, which weren’t in great shape to
begin with, and I probably should have removed the rocket plants earlier than I did.
But after that, the plants grew really strongly, and filled out all available space.
By the time the heads were large enough harvest, the younger leaves had developed that same
decayed or dried tips that I’d noticed in the Intensive Garden, but there wasn’t any
signs of phosphorus deficiencies.
And this led me to believe that while I may not have been watering enough, the soft rock
phosphate that I had added to the soil at the beginning of the season, was having a
positive impact.
The cauliflower from this garden was beautifully white, thanks to the natural shading from
the density of foliage, and the heads were generally quite large too, about 50% heavier
than in the Intensive Garden, despite the closer density and the competition from other
crops.
One of the heads was noticeably smaller than the others, but I’d accidentally pulled
this plant up when I was removing the remains of the rocket or arugula crop, which is possibly
another reason to avoid intercropping.
The crop from the No-Dig Garden did really poorly, despite the abundance of compost and
lots of space for each plant.
I'm assuming that this is because of an experiment that I had tried.
Friends of mine have a small apple juice pressing business, and we were talking about how I
might be able to make use of the abundance of apple pulp that is left over after the
juice is pressed out of it.
And I decided to try to use it as an overwintering mulch on areas of the No-Dig Garden, including
the bed that this cauliflower grew in.
This mulch layer was quite wet for most of the winter, and well into the cool wet spring
that we had, but there was a lot of worm activity throughout it, so I wasn’t too worried.
I’m not sure what the actual issue was, whether it was too acidic, or hadn’t had
enough time to decompose, or some other biological or nutrient based issue.
Things might have been better if I had added the thick layer of compost much earlier, to
allow things to settle down a bit.
But in the end the plants grew quite slowly, especially for the first few weeks after transplanting,
and a lot of the older leaves developed a strange discolouration.
The harvest was quite disappointing.
Some of the heads were ok, though quite a bit smaller than they could have been, and
there was a lot more slug damage on the surface of the cauliflower, than I’d seen in some
of the other gardens, and some of the other heads I just abandoned or threw out.
The cauliflower heads harvested from the Extensive Garden were substantially larger than in the
other gardens, about twice as heavy as from the Intensive Garden, despite having less
overall fertility.
And I imagine that this is simply due to each of the plants having a lot more space.
There were some signs of phosphorous deficiencies in the older leaves, so the plants weren’t
entirely healthy, but the smallest leaves of the mature plant were in great shape.
The heads were generally a lot more yellow than from the other gardens, but this was
due mainly to the wider spacing of the plants, which left the heads more exposed to the sun,
at least where I didn’t fold in the leaves or tie them up.
The cauliflower heads were definitely more dense than in the other gardens, with more
tightly packed curds, and part of this could be because I harvested them a little bit earlier,
because they already seemed big enough.
Looking over all the final data from the four gardens, I calculated that I harvested a total
of 7.7 kg from the six plants in the Extensive Garden, or just over 3 kg/m2.
The Intensive Garden produced 4.8 kg from the seven cauliflower plants, after the one
mouldy head was thrown out.
But the area that it was grown in was smaller than in the Extensive Garden, so the kg/m2
yield was almost the same.
The No-Dig Garden produced 3.2 kg from six cauliflower plants, or perhaps a little bit
more than 4 kg if you include the two plants that I had abandoned.
But this was spread over a larger area, than even in the Extensive Garden, so the edible
yield ended up being as low as 1.3 kg/m2.
The Polytunnel Garden was definitely the star in terms of yield, producing 7.5 kg from the
8 cauliflower plants.
But with the plants spaced so close together, this translated into an impressive 5.2 kg/m2,
and that’s despite the overshadowing, the competition, and the excessive heat.
Looking at all the data, and how the plants developed, there’s definitely room for improvement
with all of these gardens.
Making sure that there’s always enough soil moisture will definitely help, especially
in the Intensive and Polytunnel Gardens, where there’s a much closer spacing of plants.
The soil amendments that I’m planning to add to the Extensive Garden should help a
bit, more compost will definitely improve things in the Intensive Garden, and the No-Dig
Garden will definitely produce more if I forget about adding any more apple pulp.
Sowing cauliflower a bit earlier in the Polytunnel will help to avoid some of the heat, and reduce
the impact of competition from other plants later in the season, and I’ll definitely
be careful about intercropping in the future.
Out of all of this, I think that the Extensive Garden was probably the most successful this
season.
The heads were clean, dense, with a good yield, though perhaps a bit too big for some people,
and it used less fertility.
But more importantly, I was surprised at how good the cauliflower from this garden tasted,
which is possibly the most important quality, and this was confirmed in a taste test that
I organised while teaching a permaculture course.
All 17 participants agreed that the cauliflower from the Extensive Garden was definitely the
tastiest, describing it as having a full, rich, sweet flavour, without being too bitter,
and this was even though some of them were initially put off by the yellowish colour.
Most people expected the beautiful white cauliflower from the polytunnel garden to taste best,
but were disappointed that it was bland in comparison.
The cauliflower from the other two gardens were fine, but not as good as the Extensive
Garden.
Of course this small sampling is not definitive, and next season the results could be very
different, but it seems to reinforce the recommendations of Steve Solomon, on whose work the Extensive
Garden is based, that it’s better to give plants lots of space, especially if you don’t
think there’s going to be enough rainfall or watering.
This season, the Extensive approach seems to have paid off in terms of taste, yield
and quality, and that’s without having adequately remineralising the soil of this garden yet.
It will be very interesting to see just how good the taste and yield could get.